1. Field of the Invention
The present invention relates to novel antianaphylactic and antibronchospastic piperazine derivatives, to isomeric mixtures, individual enantiomers and pharmaceutically acceptable acid addition salts thereof, to a process for their preparation and to pharmaceutical compositions comprising same with a pharmaceutically acceptable carrier or diluent thereof.
2. Description of the Prior Art
In U.S. Pat. No. 3,244,718, certain carboxamido piperazine derivatives of benzhydryl type are described which are useful as antihistaminic, antiserotonin and antiallergic agents, and while it is reported that the phenyl ring attached via the carboxamidoethyl radical to the piperazine moiety may be variously substituted, in the preparative examples only one specific instance is noted wherein said ring is substituted, by a trifluoromethyl group, but here the benzhydryl group is conspicuously absent.